Extremely High Axial Loads on 2 piers

Question:

Hi
The questions are raised in my model shown below.
May be it is due to wrong elastic links for Pot Bearings specified? which i am not able to find out.




Attached herewith please find the Midas Civil model. Please assist!

Regards
 
Answer:
Hello,

Thank you for your patience.

The issues you sent were due to boundary conditions. Since there is the substructure, please remove the boundary condition for dx, dy, dz in the upper two points (marked with black circle in the below image). Then you can get the analysis results as shown below.

Thank you.

Best regards,
Jihong Hwang

Hi

Thank you for your reply.
Your advice to remove the boundary condition for SDx, SDy, SDz in the upper two points indicated is not what i intended for this model.
Actually, the two points are locations of Pot Bearings intended for the steel truss bridge to sit on. By removing the boundary condition there, the steel truss bridge will just sit on pier crosshead without any pot bearing which is not what i want. There are four pot bearings defined at four corners of this steel truss bridge.



Node 33 to node 816 defined with Pot Bearing element stfffness of SDx = 450 kN/mm, SDy = 450 kN/mm and SDz = 450 kN/mm. This is intended for a fixed joint.

Node 1 to node 815 defined with Pot Bearing elemen stiffness of SDx = 450 kN/mm, SDy = 2 kN/mm and SDz = 450 kN/mm. This joint is intended for it to slide at transverse direction but fixed at longitudinal direction. .


Node 17 to node 817 defined with Pot Bearing elemen stiffness of SDx = 450 kN/mm, SDy = 2 kN/mm and SDz = 2 kN/mm. This joint is intended for it to slide at both transverse and longitudinal directions.
Node 49 to node 818 defined with Pot Bearing elemen stiffness of SDx = 450 kN/mm, SDy = 450 kN/mm and SDz = 2 kN/mm. This joint is intended for it to be fixed at transverse direction but can slide at longitudinal direction.

The above are normally defined for pot bearings under steel truss bridge.

However, the elastic links that i have defined for this model to simulate the above requirement seems have something very wrong, based on the results obtained as highlighted before.

Please eveluate and check what is wrong with this model.

Regards


Hello,


The part I was talking about is support which is applied on node no.1 and 17 not elastic link. To consider the pot bearing as elastic link, the support of nodes at points 1 and 17 should be deleted.

Have a nice day!
Thank you :)

Best regards,
Jihong Hwang
Creation date: 7/24/2018 10:43 PM (dklee@midasit.com)      Updated: 7/25/2018 8:13 AM (dklee@midasit.com)
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